128523 has 4 divisors (see below), whose sum is σ = 171368.
Its totient is φ = 85680.
The previous prime is 128521. The next prime is 128549. The reversal of 128523 is 325821.
It is a semiprime because it is the product of two primes.
It is not a de Polignac number, because 128523 - 21 = 128521 is a prime.
It is a D-number.
It is the 359-th Hogben number.
It is a Duffinian number.
128523 is a lucky number.
It is a self number, because there is not a number n which added to its sum of digits gives 128523.
It is not an unprimeable number, because it can be changed into a prime (128521) by changing a digit.
It is a nontrivial repunit in base 358.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21418 + ... + 21423.
It is an arithmetic number, because the mean of its divisors is an integer number (42842).
2128523 is an apocalyptic number.
128523 is a deficient number, since it is larger than the sum of its proper divisors (42845).
128523 is an equidigital number, since it uses as much as digits as its factorization.
128523 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 42844.
The product of its digits is 480, while the sum is 21.
The square root of 128523 is about 358.5010460236.
The cubic root of 128523 is about 50.4653881708.
The spelling of 128523 in words is "one hundred twenty-eight thousand, five hundred twenty-three".